Metal tubular frame structure and method of fabricating the same



Sept. 4, 1934. D, F. MCMURCHY METAL TUBULAR FRAME STRUCTURE -AND METHOD OF FABRIQATING THE SAME Filed Aug. 17, 1932 2 Sheets-Sheet l ATTORNEYS Sept. 4, 1934. D, McMURcHY 1,972,309

METAL TUBULAR FRAME STRUCTURE AND METHOD OF FABRICATING THE SAME Filed Aug. 17. 1932 2 Sheets-Sheet 2 INVENTOR Dona/d E McMz/rchy BY it ina/e25 Vs Patented Sept. 4, 1934 uNiTEo SrA PATEN O E METAL TUBULAR FRAME STRUCTURE AND METHOD OF FABRICATINGTHE SAMEI Donald F. McMurchy, Belle" Harbor, N. Y., as-

signer to Standard;Gas Equipment Corpora tion, a corporation of Maryland Application August n, 1932, Serial N o. 629,088 1 5 Claims. (c1. 11a+11 s) This invention relates to metal tubular frame structures and to a method of fabricating the same The invention in one of its aspects consists essentially of cutting out a portion of one-tubular member for a part of its length, and bending-it at an angle in the region of the uncut portion whereby a pocket is formed within the' edges of the cut-out portion and the intersecting faces of the uncut portion. Two tubular legs or sections are thus provided radiatingindifferent directions from the pocket which preferably is of the same configuration as'the section of the tubular members used. A second tubular mem ber is positioned within the pocket thus formed in the first member, and, consequently; meets the plane of the radiating legs at their point of intersection. The pocket is of such size'that a snug fit is provided between the two tubular members when they are joined together.

Where the'tubular members usedareoi the flat-wall type, for instance square in cross section, the length. of the cut -away portion will equal the width'of 'two sides of the member with which it is to be associated, so'that in the finished construction the member within the pocket will have two of its sides in contact with the right angle faces of the uncut portion of the bent member, and the other two Of 'itS sides in contact with the edges of the cut-outportion or, what is the same thing, the endsof the right angularly disposed legs. v a Y The two members are preferably! secured to gether by spot welding theintersecting faces of the uncut portion of the one member to thecontacting sides of the other member, but, if de; sired, any other method ofwelding or riveting maybeused.

In the. accompanying drawings; Fig. 1 is a perspectiveview of one'frame member before the bending operation; v 4.

Figs. 2, 3 and 4. are perspectivegviews showing different ways of fabricating the frame. members; H Fig. 5 is a perspective view of 'aframemember, incised and cut to embody theinvention'in a modified form; 7 1: 4;

.Fig. 6. is a perspective view, showing the member of Fig. 5-bent and shaped around a second member in'the fabrication of a tubular-frame structure; '1 Fig. 7 is a horizontal sectional plan view on the line 7-7 of Fig. 6;

Fig. 8 is aside elevation of a frame'membe'r instill-another modified form before being bent to assemble it in-the frame structure;

Fig, 9 is a sectional plan view showing a member of the form of Fig. 8 incorporated in the frame structure; and

Fig. 10 is a sectional elevation on the line 10-10- of Fig.9, as viewed in the direction' of the arrows on said-line. I 1 1 Referring particularly to Fig. 1, a hollow tube member 10 is shown of a character suitable for practicing the invention. 7 I

' The type of tubing employed is preferably of thehollow seamless type, and has a cross section of suitable geometrical shape. The cross section of the member shown is square, as tubing of this character lends itself more readily to the fabrication of 'frame structures with the type of joint herein disclosed; r

The completed joint is depicted in Figs. 2, 3 and 4, and shows a member 11 positioned within a pocket 12 at the intersection of two radiating legs 13 and 14 of the member 10. 1 p Ini forming the pocket 12, three sides of 'the member: 10 are cutout for a portion of its-length, as at 15, leaving one side 16 uncut or intact and forming a web, as shown, joining the-sections 13 and it, which constitute the radiating legs when the member is bent. The length of the cut-away portion 15 or the distance between the opposed ends '17 and 18 of the sections 13 and 14 ispreferably equal to the -length; of two sides of theother tubularmemberll. "The member 10 is then bent at right angles in the region of the uncut portion lfi substantially midway between the section ends 17 and 18, until these ends meet along one end, as shown. for example, in Fig. '2. The member 11 may serve as a guide in the bending process and, in fact, it will often be found desirable to bend the member 10 around the member 11 with which it is to be associated. i I

r The four-sided pocket 12 above referred to is thus formed by the opposite ends 17 and 18-of the sections 13 and 14, and the inner faces 16 and 16" of the uncut side or web 16 which are now standing at right angles to each other. The pocket thus formed is of such size that the'member -ll positioned therewithin is held snugly in position.

The joint can be formed at any position along the unbent member 11, and in Fig. 2 is shown constructed at the end. In Fig. 3, the unbent member 11 is shown as a vertical element with the joint formed at an intermediate point in the length thereof. r V In order to'holdthe two-members l0 and 11 tical members which carry a compressional load do not have to be cut out asiin the case-of a mortised joint and can, therefore,' support, a

greater load without buckling thanif a mortised joint were used. Any load whichthe horizontal legs 13 and 14 in Fig. 3 would be called uponto';

carry is amply supported by the shearing strength of the uncut portion 16 which joins them together.

Fig. 4 shows the joint as formed at the top of a structure. The joint is formed in the'same manner as previously described, .butin thiscase, the unbentmember 11 is the horizontal one,.whereas the bent member 10 has its radiating legs-13 and 14 extending one in a vertical direction, and the other in a horizontal direction. In this case, the load would be carried by the horizontal unbent member. 11 or the horizontal leg 14 of thebent member. Here again the vertical leg 13 is able to offer its full strength to support the load imposed on the horizontal unbent member 11, since this latter member rests squarely on the upper end 17 of thevertical leg 13. There need be noiout-out portion in the vertical leg between this upper end and its lower end that would tend in any way to weaken the member, as in the case of a mortise joint. Furthermore, any bending tendency resulting from a load applied on the horizontal leg 14 of the bent member in a joint of this char acter, would be amply resisted by the vertical. end 18 abutting the uncut face of the horizontal un bent member 11.

In Figs. 5, 6 and 7 a modification of the invention is shown, and wherein flaps are formed on the adjacent end of the sections of the bent member, to aid in the firm connection of thesame in the frame structure. On reference to Figs. 6 and 7, it will be seen that two flaps 20 extend in opposite directions from the inner end of the sec-. tion 13 of the member 10, and are seated against one side of the vertical member 11 while similar flaps 21 extend in opposite directions from the inner end of the other section 14 and are seated against the adjoining side of said vertical member; and a further flap 22 extends from the inner end of one of the sections, in the presentv instance the section 13 and is seated against the adjacent side of the other section 14%. By spot welding these flaps to the parts with which they contact, or by otherwise connecting them with said parts, a very secure and'firm attachment of the members may be obtainedand the sections of the bent member will be firmly braced at their points of connectionuwith the vertical member, and will be preventedfrom sagging or displacement. u

The several flaps areformed on the member 10 by incising and cutting the same, as shown in Fig. 5, where it will be seen that incisions 23, 24, 25 and 26 are made in the four corners of the member for a portion of its length, and the three walls of the member are cutthrough transversely as at 2'7, 28 and 29, these cuts intersecting the several incisions and leaving the wall or web 16 intact. Then the portions of the three walls freed by the several cuts and incisions are bent outwardly at right angles, thereby forming the twofiaps 20, the two flaps 21, and the flap 22 before alluded to, which, in the bending of the member around the vertical member as shown in'Fig. 6, will occupy the relations therein illustrated and above described. The flap on the section 14? corresponding to the fiap 22 will, in the assemblage of the member 1G on the vertical member, be bent and housed in its connected section out of'the way, as shown in Fig. 7.

In Figs. 8, 9 and 10, the. frame member 10 which is to be bent, is'shown in still another modified form to adapt the same in the fabrication of tubular frame structures in which the members of the frame are of cylindrical form or circular-or substantially so in cross section, as distinguished from frame members of the fiatwall type angular in cross-section, as in the other forms of the invention hereinbefore described[ In Fig. 8, it will be seen that the member'lo has the upper and lowerand forwardportions of its circular wall-cut, outv as at, 15 thereby producing two sections 13 and 14 connected together by the intact rear wall portion or web 16*.

To cause the two sections of the member thus formed to fit snugly at their ends against the vertical tubular member 11 when the wall or intactweb. 16 is bent around the vertical memher as shown in Fig. 9, the upper andlower edges of the inner adjacent ends of the two sections 13 and 14 are formed with recesses28 of a curvature corresponding to the externalcontour of the vertical cylindrical member, whereby the said sections will fit snugly around thesides of the said member 11 as shown inFig. 9. And where the adjacent edgesof the two sections come to gether in the angle between said section; the said edges are formedso'that they will interfit with 'eachother, one of the edges being provided with a concavity orrecess 29, and the other being formed with a convex terminal portion 30 to fit and seat in said cavity.

,In this manner the member. 10 when bent around the vertical member 11 as shown in Fig. 9, will contact throughout its edges with the curvedexternal surface of{the'm ember 11 and theadjacent edges of thetwo sections where they meet, will interfit one in the other, thereby producing. a 'smooth'joint between the bent member and the unbent member of the'struct'ure.

It will be understood as in the foregoing forms of the invention, that the parts thus assembled may be heldin fixed relation by welding or; other connecting means between the contact surfaces of the assembled members. a

' While the invention hasbeendescribed as embodied in flat-wall tubular members rectangular in cross section, and in tubular members circular in cross-section, the invention is not necessarily limited to members of this. form, as there are many other tubular shapes'that could bereadily substituted, as, for instance, tubular members having a triangularcross-section and other crosssections- I There are numerous uses to which a frame structure fabricated in the foregoing manner maybe put,.and-. there is no need of placing undue emphasis upon any particular use, although it maybe stated that the structure has been found especially'suitable for furniture, gas ranges and Y the like, where lightness. with strength: and rigidity are advantageous. As will be apparent, the structurewhen completed will present a neat, and attractive appearance andiwill-lend itself-to finishing orgraining in simulation of woodwork.

Having thus described my invention, what I claim is:

1. In the method of fabricating a frame structure composed of tubular members, incising one of the members longitudinally at a number of points for a portion of its length, cutting certain of the portions of the member located between said incisions transversely through the incisions substantially midway of the length of the same to leaveone of said portions intact, bending the portions freed by said incisions and cuts sub 'stantially at right angles to the member to form a plurality of flaps, bending the intact portion of the member about a second member to cause the bent portion, the flaps, and the portions of the member at the points of union of the flaps therewith, to contact with the walls of a second tubular member, and securing the contacting parts of said members together.

2. In the method of fabricating a frame structure composed of flat-wall tubular members, incising one of the members longitudinally at its corners for a portion of its length, cutting certain walls of the member transversely through said incisions substantially midway of the length of the same to leave one wall intact, bending the portions of the walls freed by said incisions and cuts substantially at right angles to the member to form a plurality of flaps, bending the intact wall of the member about a second member to cause the bent wall, the flaps, and the portions of the member at the points of union of the flaps therewith, to contact with the walls of said second member, and securing the contacting parts of said members together.

3. In the method of fabricating a framestructure composed of fiat-wall tubular members, incising one of the members longitudinally at its four corners for a portion of its length, cutting three walls of the member transversely through said incisions substantially midway of the length of the same, thereby leaving one wall of the member intact, bending the portions of the walls freed by certain of said incisions and cuts at substantially right angles to the member to form a plurality of flaps, and bending said intact Wall of the member about a second member to cause the bent wall, certain of the'fiaps, and the portions c of said member at the points of union of the flaps therewith, to contact with the walls of said second member, and securing the contacting'parts of said members together.

. 4. A, tubular frame structure comprising in combination a tubular member angular in cross section, a second member consisting of two spaced tubular sections angular in cross section and connected together by a web bent around the first member, with the adjacent ends of the tubular sections abutted against adjoining sides ofthe first member, a plurality of flaps projecting laterally from the ends of the tubular sections of the second member and seated against said sides of the first member, a single flap projecting laterally fromsthe end of one of said tubular sections and seated against the adjacent side of the of the first member, two flaps projecting in oppothe second member and seated against the sides of the first member, a further fiap projecting laterally from the end of one of said sections and seated against the side of the other section, and

means for fastening said members together at L' their contacting surfaces.

DONALD F. MCMURCHY.

site directions from the end of each section of 

